Electric Arc Furnace Dust Research Articles

Comparison of reduction kinetics of Fe2O3, ZnOFe2O3 and ZnO with hydrogen (H2) and carbon monoxide (CO)

Electric arc furnace dust (EAFD) recycling is based on the reduction of oxides containing iron and zinc. With regard to the sustainability of industrial processes, hydrogen reduction processes could be the key technology to replace current recycling technologies based on carbothermal reduction. In this context, hydrogen is often claimed to provide better reduction kinetics, but it is mostly unclear how much faster it is. The present work gives a comprehensive comparison of the reduction kinetics of the major zinc- and iron-containing oxides in EAFD (Fe2O3, ZnOFe2O3, and ZnO) using hydrogen and carbon monoxide under various process parameters. The influence of specimen size, reduction gas flow rate, and temperature were evaluated. The kinetic advantage of hydrogen compared to carbon monoxide was confirmed, enabling the reduction of direct CO2-emission. Hydrogen results in a 2.5 times faster reduction of Fe2O3 and a doubling of the reduction rate for ZnOFe2O3. ZnO reduction was determined to be 1.5 faster. Furthermore, ZnO was found to be the rate-limiting substance in the recycling of EAFD, regardless of the reducing agent.

Lead and zinc selective extraction from EAF dust while heating in resistance furnace with flowing argon

The elemental and phase compositions of electric arc furnace (EAF) dust from PJSC Severstal were studied. We carried out the thermodynamic modeling of zinc and lead selective extraction process and determined its possible mechanisms. EAF dust was heated in the temperature range of 20 – 1300 °C in vacuum resistance furnace and the Tamman furnace with flowing argon. Experiments in the vacuum resistance furnace with linear heating showed that lead and zinc removal from the sample occurs in the temperature range of 800 – 1200 °C, with higher lead removal rate. Intensive lead removal was observed at temperature above 1000 °C, while intensive zinc removal occurs at temperature above 1200 °C. Clarifying isothermal experiments performed in the Tamman furnace showed that lead complete transition to the gas phase was achieved at a temperature of 1100 °C (holding time – 12 min) and at a temperature of 1200 °C (holding time – 6 min or more). At the same time, zinc removal was observed in the amount of 14.4 % ratio and 32.2 % ratio, respectively, which allows us to conclude that it is possible to consistently obtain two products: lead and zinc mixture and zinc not contaminated with lead. When comparing experimental and thermodynamic modeling data, the reactions that are most likely to occur during the carbon reduction of lead- and zinc-containing phases were determined.

Utilization of Radioactive Contaminated EAF Dust as Material for Making Paving Block

Electric arc furnace dust, due to steel fabrication by-products, some of that material has been contaminated with radioactive materials from orphan sources. After calculating the concentration of radionuclide activity, it is known that the material meets the criteria for clearance of application and can be used for other purposes according to the appropriate characteristics. By determining the clearance, EAF dust will be processed through a stabilization/solidification method to be used as a material for making paving blocks. Through elemental analysis of EAF dust using the Micro-XRF method, it is known that sample 1 has a Ca content of 3.9%, CaO is 5.51%, Si is 0.64%, and SiO2 is 1.36%, while sample 2 has Ca content. 4.8%, CaO 6.74% Si 0.63% and SiO2 1.34%. The compressive strength test results based on Indonesian National Standard (SNI) 03-0691-1996 give the results of paving blocks included in quality D with a value of 9.2 MPa which can be used for parks or other purposes. In the calculation of cost savings analysis, determining the clearance for EAF dust can provide cost savings of Rp. 205,562,000 compared to if it had to be managed as radioactive waste. The production cost for one paving block using a mixture of EAF dust is Rp. 2,213.77 or Rp. 97,405.88 for units per m2.

Evaluating the Concentration and Leachability of Heavy Metals in Electric Arc Furnace Dust: Implications for Environmental Management

With the expansion of steel production via electric arc furnaces, an increase in dust generation—a by-product of these operations—poses substantial challenges. These difficulties stem from land use restrictions for large-scale dust waste storage and the environmental implications of heavy metal contamination inherent in the dust. In an effort to promote the repurposing of this potentially hazardous solid waste, this study examines the concentration and leachability of various heavy metals in this dust. Digestion of the dust samples was carried out in a controlled laboratory setting, after which the concentrations of iron (Fe), magnesium (Mg), zinc (Zn), manganese (Mn), nickel (Ni), lead (Pb), cadmium (Cd), and cobalt (Co) were determined using flame atomic absorption spectrometry. The mean concentrations of these heavy metals in the dust were found to be in the following descending order (in mg/kg): Fe> Mg> Zn> Mn> Ni> Pb> Cu> Cd> Co. Water leaching tests were subsequently conducted, revealing that Co and Cd exhibited the greatest leachability at varying pH levels. Conversely, Fe and Ni displayed minimal leachability. These findings have significant implications for the reuse and environmental management of electric arc furnace dust.

The Effect of Electric Arc Furnace Dust (EAFD) on Improving Characteristics of Conventional Concrete

The steel industry is one of the key industries and its use is inevitable in many industries including construction. In addition to steel, this industry produces massive amounts of electric arc furnace dust (EAFD) that is classified as hazardous waste. Using this material as an admixture can improve the characteristics of concrete, neutralize potential risks and be beneficial to the circular economy. Considering the differences in EAFD between different steel companies, which in turn is caused by the type and percentage of input materials, the optimal percentage and specific application of EAFD from steel companies of each region is unique. In the present study, samples from 11 different sources of EAFD in Khuzestan Steel Company (KSC) were collected. Then, they were classified into three groups depending on the size and origin (fine and coarse, both obtained by filtering those particle sizes directly from furnaces, and a third class obtained in the interior of the steelmaking site close to material handling (MH) belt conveyors) based on their physical and chemical characteristics. To test the effect of EADF as an admixture, several conventional concrete samples were prepared by replacing 0% (control), 2%, 5% and 8% of cement with each EAFD group. Finally, the resulting material was characterized through several tests, namely: (i) compressive strength test at 7, 28 and 90 days, (ii) depth of water penetration under pressure test and (iii) electrical indication of concrete’s ability to resist chloride ion penetration. The result shows that replacing 2% of the cement with MH caused the largest improvement in compressive strength of 7 day concrete, but also showed negative effect on water penetration, while coarse had a negative effect in almost all tests except in the chloride ion penetration test. The best results were obtained by replacing with 2% of cement with fine EAFD, showing significant improvements in all tests, as well as in the observed trend of increasing compressive strength over time.

Treatment of strong alkaline wastewater from neutral leaching of EAF dust by precipitation and ion exchange

Neutral leaching or water washing is used for Cl− and partially Ca2+ ion removal in order to save the leaching reagents for the next steps in hydrometallurgical treatment of electric arc furnace dust. This pre-treatment of the material leads to the generation of strong alkaline (pH = 11.9–12.7) leachate (wastewater), which underlies precipitation of Ca and other accompanying metals. This work presents results from the study of various economically differing (cost and time) techniques for elimination of these disadvantageous phenomena. The aim of the experimental study was to obtain water suitable for reuse in the leaching or for discharge into a recipient in accordance with valid legislation. The experiments were focused on the removal of precipitates, or metals which create the precipitates, and pH decreasing. Our results indicate that five-minute agitation of 4 g solid NaHCO3 and 1 L of neutral leachate and subsequent ion exchange in the sequence of strong-acid cation and strong-base anion exchange treatment led to the acquisition of water without creation of precipitates, with pH below 8.5 and conductivity approx. 0.03 mS. The removal of Cl− ions was not complete.

Zinc Precipitation from Ammonia Leaching Solutions of Electric Arc Furnace Dust by Carbon Dioxide

Zinc Precipitation from Ammonia Leaching Solutions of Electric Arc Furnace Dust by Carbon Dioxide

Manufacturing, curing and mechanical testing of BREX from electric arc furnace dust

At present the acute issue is utilization and recycling of metallurgical production wastes; one of which is electric arc steelmaking dust (EAF). In Russia there are up to 30 million tons of dust in the dumps of metallurgical plants and additionally up to 780 thousand tons are added to this amount annually. Considering the amount, the main value is zinc, which content reaches 25 wt%, as well as iron, which content varies from 20 to 50 wt%. The paper presents the results of studies on briquetting of the EAF dust using the technology of stiff extrusion and obtaining brackets. The chemical composition of the initial EAF dust was studied by X-ray spectral analysis using JEOL JSM-7001F electron microscope. The amount of reducing agent was selected based on results of thermodynamic modeling using the TERRA software package. The BREX were produced in a laboratory extruder assembled from an electric motor, a reduction gear, a screw, and a die. Two types of dies were used in the briquetting study. For each type the optimum moisture and binder were selected. The influence of the binder and moisture on the quality of the finished briquettes was evaluated. The BREX drying was studied in order to find out the optimum curing time in the air. In addition, drying at 110 °C was carried out for a comparative assessment of the strength of briquettes depending on the method of drying. The drop tests of the finished briquettes were carried out according to GOST 25471‒82 “Iron ores, sinter and pellets; method for determining dumping strength”. The test results showed the possibility of transportation of the EAF dust briquettes

Pyrometallurgical Technology for Extracting Iron and Zinc from Electric Arc Furnace Dust

This study is aimed at developing a technology for processing electric arc furnace dust (EAFD) into granulated cast iron and a zinc-containing product. The study object was the dust from the EAF of PJSC Magnitogorsk Iron and Steel Works (Magnitogorsk, Chelyabinsk region). It has been established that the dust contains valuable components in the form of ZnFe2O4 and ZnO. The processing of EAFD involves the reduction of Fe and Zn in a charge from their oxygen-containing forms with C and CO. The content of the charge components was calculated in % as follows: EAFD—17.44; scale—51.33; hard coal—20.61; quartz sand—4.71; lime—5.91. The experiments in the high-temperature LHT 08/17 furnace (Germany) allowed for defining the optimal temperature regime for reduction melting. As a result of laboratory tests, granulated pig iron samples were obtained, containing in wt%: Fe—95.27; C—4.4; S—0.07, and others. Captured zinc-containing product after calcination (to remove halogens) contained 90.21 wt% ZnO. The resulting granulated pig iron is recommended as one of the charge components in electrometallurgical steel production. The zinc-containing product is recommended as a raw material for Zn production and others.

Reduction Behaviour of Electric Arc Furnace Dust (EAFD)-Coal Composite Pellet in a Muffle Furnace

Reduction Behaviour of Electric Arc Furnace Dust (EAFD)-Coal Composite Pellet in a Muffle Furnace

Electric steelmaking dust as a raw material for coagulant production

The paper describes the issues associated with waste generated during steel production and processing, in particular the dust from electric arc furnaces (EAF). An effective solution for the disposal of such waste is its involvement in processing to obtain valuable products. This paper studies the physical and chemical properties of EAF dust produced during the smelting of metallized pellets and captured by the dust and gas cleaning system of the steel-smelting shop at the Oskol Electrometallurgical Combine, Belgorod Region. The results obtained in the study of the chemical and disperse compositions of dust, the microstructure of the surface made it possible to propose the use of dust as a raw material for coagulant production. The conditions of acid-thermal treatment of dust are determined, contributing to the partial dissolution of iron (II), (III), and aluminium compounds, which ensure the coagulation processes during wastewater treatment. Model solutions show high efficiency (> 95 %) of water treatment from heavy metal ions by modified EAF dust.

Analytical Study on the Effect of Electric Arc Furnace Dust (EAFD) on the Rutting of Asphalt Concrete Mixtures

As a byproduct of the steelmaking process, significant amounts of hazardous electric arc furnace dust (EAFD) are produced. Utilizing the solidification/stabilization technology with asphalt mix is one way to safeguard the environment from its negative effects. Rutting was used as an indicator to assess the asphalt mixture with EAFD since it is an important factor in pavement design. This study's major goal is to ascertain how EAFD affects the rutting of asphalt-concrete mixtures. To evaluate the ideal asphalt content, the Marshall test method was applied to asphalt concrete mixtures. EAFD was added to the asphalt cement in four different volume percentages as a binder addition. Then, using the Universal Testing Machine, participants were exposed to a replica of the rutting test (UTM). Experiments were conducted at 25, 40 and 55oC, and at frequencies of 1, 4 and 8 Hz. Rutting was measured for each specimen. Tests results showed that while rut depth has negative correlation with of EAFD% and positive correlation with the temperature. The use of EAFD has dual advantages, protecting the environment from the adverse impact of EAFD and reducing the cost of asphalt mix without jeopardizing the pavement performance.

Rational fabrication of low carbon foot-print electrode materials for lithium-ion batteries from electric arc furnace dust via integrated hydrometallurgical process

Transforming industrial waste into high-value-added products represents a new avenue in the field of material science. This paper puts forward a comprehensive example for future works which target fabricating low-carbon footprint electrodes for rechargeable batteries. Within this scope, first time in the open literature, an integrated hydrometallurgical process has been designed to fabricate metal oxide powders of different properties from electric arc furnace (EAF) dust. Leaching, cementation, distillation, chemical precipitation, and calcination are used to produce powders rich in zinc oxide (Sample 1), ferrite (Sample 2), and nanocomposite (Sample 3) from the electric arc furnace flue dust.While sample 1 (zinc oxide with 97.8% purity) may be used in optics and other engineering applications, sample 2 (rich in zinc ferrite) and sample 3 (made of nanocomposites) that are recovered from the EAF dust may be utilized as electrode active material in lithium-ion batteries: Sample 2 and Sample 3 retain 43% and 50% of their capacities after 125th cycle, respectively. To further improve the cycle performance of Sample 2, the powder rich in ferrite is mixed with nickel salt, then heat treated. The latter performs 65% capacity retention after 125th cycle. The fact that every fabricated electrode achieves 125 cycles with success demonstrates the viability of the proposed technique; thus, various procedures may be developed to further elaborate the use of various industrial wastes in electrode fabrication.

Composite High-k Films Based on Polyethylene Filled with Electric Arc Furnace Dust and MWCNT with Permittivity Synergetic Effect

The production of three-phase composites is a relevant and effective approach to obtain materials with the required mechanical and dielectric properties. In this work, dust, which is a waste product of steelmaking and is formed during the gas cleaning of electric arc furnaces at the production base of Severstal, was used as a functional filler for the low-density polyethylene polymer matrix. The fractional, elemental, qualitative, and quantitative phase composition of the native dust was studied using laser diffraction, energy-dispersive X-ray phase analysis, and X-ray fluorescence spectrometry. An increase in the permittivity of the dust was achieved due to its reduction in a hydrogen atmosphere and, as a consequence, a change in the elemental and phase composition causing an increase in the concentration of metallic iron. Composite films were obtained using a blending roll mill at temperatures of 130 and 140 °C. The concentration of the main filler was 18.75, 37.5, and 75 wt.%. Additionally, a conductive additive in the form of MWCNTs was introduced into the composition of the composites in an amount of 0.25 wt.%. The uniformity of the filler distribution in the polymer matrix was assessed from electron micrographs. The dielectric properties of fillers and composite films based on polyethylene filled with electric arc furnace dust and MWCNTs were studied using impedance spectroscopy in the frequency range of 10–106 Hz. The use of reduced dust at a concentration of 25.8 vol.% combined with 0.25 wt.% MWCNTs in the composition of the composite film provided an increase in ε′ to 13.5 at tan δ = 0.038. Thus, three-phase polymer matrix composites based on LDPE using dust as a filler with a conductive microadditive of MWCNTs have a synergistic effect, which manifests itself in an increase in the permittivity and a decrease in dielectric losses.

Mechanisms and kinetics of zinc and iron separation enhanced by calcified carbothermal reduction for electric arc furnace dust

Mechanisms and kinetics of zinc and iron separation enhanced by calcified carbothermal reduction for electric arc furnace dust

Study for Manufacturing of Zinc Sulfate from Electric Arc Furnace Dust by Hydrometallrugical Process

본 연구에서는 제강분진으로부터 습식제련을 이용하여 아연을 선택적으로 회수하고 황산아연을 제조하고자 하였다. 제강분진의 성상분석을 통해 기존의 제강분진과 다르게 철의 함유량이 9.9%로 상대적으로 낮고 망간이 19%로 다량 함유되어 있었으며 이에 알맞은 습식제련 공정을 설계하였다. 침출공정에서는 고액비, 온도, 황산 농도별 실험을 통해 1.6M 황산, 20% 고액비, 60℃, 1시간동안 침출하여 85%의 아연, 망간을 용해시키고 철은 침출되지 않았다. 망간으로부터 아연을 선택적으로 회수하기 위해 D2EPHA를 사용한 용매추출 공정을 선택하였고 0.8M D2EHPA, 32% 비누화도, O/A 비 2, 향류 3단 추출을 통해 에서 99% 아연을 추출하였으며, 공동 추출된 망간은 pH 1.5로 조정한 황산 수용액으로 전량 세정하였다. 최종적으로 1.5M 황산을 이용하여 O/A 비 4, 향류 4단 탈거를 통해 아연을 농축 탈거하였다. 탈거액에는 40g/L의 아연이 함유되어 있었으며 이를 감압증류하여 99.9%의 황산아연 1수화물을 획득하였다.

A Study on the Resource Recovery of Fe-Clinker generated in the Recycling Process of Electric Arc Furnace Dust

전기로에서 고철(Scrap)의 용해과정에서 발생되는 분진량은 고철장입량의 약1.5%정도이며, 주로 백필터(Bag Filter)에서 포집된다. 전기로 제강분진의 주요한 구성원소인 아연(Zn)과 철(Fe)중에서 아연성분은, 제강분진에 탄소계의 환원재(코크스, 무연탄)와 석회석(C/S제어)을 첨가하여 Pellet형태로 가공한 후에 반응로(Rotary Kiln 또는 RHF)에 장입하여 환원, 휘발, 재산화의 단계적인 세부반응을 거쳐서, 60wt%Zn을 함유한 조산화아연(Crude Zinc Oxide)으로 회수된다. 한편 제강분진 중의 철(Fe)성분은, Fe-Base의 Clinker(2차부산물)라고 하는 고형물의 형태로 반응기로부터 배출된다. 기존의 Fe-Clinker의 처리방법은, 각국의 상황에 따라서 다양한 방안들이 시행되고 있는데, 대표적인 처리방법으로는 매립, 재활용(로반재, 콘크리트용 골재, 시멘트제조용 Fe-Source), 그 외에 다양한 처리방법들이 있다. 이들 방법들 중에서 매립의 경우는, 침출수에 의한 환경오염, 고가의 매립비용, Fe자원의 낭비 등의 이유로, 결코 바람직한 처리방법이라고 할 수는 없다. 그러나 Fe-Clinker중의 Fe성분을 전기로를 이용하여 직접적으로 재활용하는 방법에 대한 연구결과는 거의 찾아 볼 수 없었다. 따라서 본 연구에서는 Fe-Clinker중의 Fe성분을 보다 적극적으로 회수하기 위한 방법으로서, 먼저 Fe-Clinker를 분쇄하고 이어서 비중선별과 자력선별을 순차적으로 실시하여, Fe-성분이 농축된 조분(Coarse particle, >약10μm)과 슬래그성분을 주로 함유한 미분(Fine particle, <약10μm)으로 분리하였다. 이렇게 분리한 조분에 탄소계 환원제(코크스, 무연탄)와 점결재(전분)를 첨가하여 단광Clinker를 제조하여, 전기로에 고철을 장입할 때에 소량(1~3wt%)의 단광Clinker를 함께 장입하여, 단광Clinker의 첨가재(가탄재, Fe-Source, 발열재 등으로서의 역할)로서의 사용가능성을 조사하였다. 그 결과, 비록 소량이지만, 전력원단위와 생산수율이 다소 향상되는 효과를 나타내었으며, 용융금속에 대한 가탄효과도 확인할 수 있었다.

Reduction Smelting of the Waelz Slag from Electric Arc Furnace Dust Processing: An Experimental Study

Waelz slag is an iron-containing waste generated during electric arc furnace (EAF) dust processing in a rotary kiln named the Waelz process. This study focuses on the reduction smelting of the Waelz slag to produce iron-based alloy. The thermodynamic simulation using FactSage 8.0 software was carried out to predict temperatures of the metal and slag obtained as well as their compositions. Based on the simulation results, reduction smelting experiments were performed on a laboratory scale using two approaches, with and without preliminary froth flotation of carbon, respectively. The experiments have confirmed the technological possibility of reduction smelting of the Waelz slag from EAF dust processing. The approach using preliminary flotation of carbon and reduction smelting at 1500 °C resulted in high-copper cast iron production, while the approach without flotation, where the Waelz slag was smelted at 1650 °C with the addition of SiO2 flux, led to obtaining low-silicon ferrosilicon with high Cu content, as well as slag attractive for construction industry.

Direct Conversion of Electric Arc Furnace Dust to Zinc Ferrite by Roasting: Effect of Roasting Temperature

Direct Conversion of Electric Arc Furnace Dust to Zinc Ferrite by Roasting: Effect of Roasting Temperature

Kinetics of Carbothermal Reduction of Electric Arc Furnace Dust from a Stainless Steel Plant

Kinetics of Carbothermal Reduction of Electric Arc Furnace Dust from a Stainless Steel Plant